Wang Hui, Yu Xiaojuan, Zhang Xu, Wang Suxia, Zhao Minghui
Laboratory of Electron Microscopy, Peking University First Hospital, Beijing, 100034, People's Republic of China.
Renal Pathology Center, Institute of Nephrology, Peking University, Beijing, 100034, People's Republic of China.
Diagn Pathol. 2021 Jul 4;16(1):59. doi: 10.1186/s13000-021-01120-4.
Chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) is rare in Asians, and patients with CLL/SLL seldomly undergo kidney biopsy. The histopathological features and clinical relevance of tubulointerstitial injury in CLL/SLL have not been extensively characterized. Hence, we attempted to describe the clinical characteristics, renal pathology and clinical outcome of a well-characterized population of CLL/SLL patients with CLL cell infiltration in the renal interstitium from a large single center in China.
Between January 1st, 2010 and September 31st, 2020, 31946renal biopsies were performed at Peking University First Hospital, and 10 CLL/SLL patients with CLL cell infiltration in the renal interstitium were included. Complete clinical data were collected from these 10 patients, and renal specimens were examined by routine light microscopy, immunofluorescence and electron microscopy.
The extent of the infiltrating CLL cells in patients with CLL/SLL varied among different patients and ranged from 10 to 90% of kidney parenchyma. Six (60%) of 10 patients presented with an extent of infiltrating CLL cells ≥50%. Interestingly, we found that three patients (3/10, 30%) expressed monoclonal immunoglobulins in the infiltrating CLL cells, and special cytoplasmic crystalline structures were found in two of the three patients by electron microscopy for the first time. Severe renal insufficiency (Scr ≥200 μmol/L) was associated with ≥50% interstitial infiltration of CLL cells in the renal interstitium.
The current study confirmed that CLL cells infiltrating the renal interstitium can directly secrete monoclonal immunoglobulins, indicating that the interstitial infiltrating CLL cells possibly cause renal injury directly by secreting monoclonal immunoglobulins in situ. This finding may prove a new clue to elucidate the pathogenetic mechanism of renal injury involved with CLL/SLL.
慢性淋巴细胞白血病/小淋巴细胞淋巴瘤（CLL/SLL）在亚洲人中较为罕见，CLL/SLL患者很少接受肾活检。CLL/SLL肾小管间质损伤的组织病理学特征及临床相关性尚未得到广泛描述。因此，我们试图描述来自中国一个大型单中心的一组特征明确的CLL/SLL患者的临床特征、肾脏病理及临床结局，这些患者的肾间质中有CLL细胞浸润。
2010年1月1日至2020年9月31日期间，北京大学第一医院共进行了31946例肾活检，纳入10例肾间质中有CLL细胞浸润的CLL/SLL患者。收集这10例患者的完整临床资料，并对肾标本进行常规光学显微镜、免疫荧光及电子显微镜检查。
CLL/SLL患者中浸润的CLL细胞程度在不同患者之间有所不同，占肾实质的比例为10%至90%。10例患者中有6例（60%）浸润的CLL细胞程度≥50%。有趣的是，我们发现3例患者（3/10，30%）浸润的CLL细胞中表达单克隆免疫球蛋白，其中2例患者通过电子显微镜首次发现了特殊的细胞质晶体结构。严重肾功能不全（Scr≥200μmol/L）与肾间质中CLL细胞≥50%的间质浸润相关。
本研究证实浸润肾间质的CLL细胞可直接分泌单克隆免疫球蛋白，表明间质浸润的CLL细胞可能通过原位分泌单克隆免疫球蛋白直接导致肾损伤。这一发现可能为阐明CLL/SLL相关肾损伤的发病机制提供新线索。
